The present invention relates to an information processing system using a coordinate input device and a display, and more specifically to an input-display integrated, pen-input information processing system, which allows the display to be carried like paper and freely laid out on a desk (coordinate input device) and which further permits two or more displays stacked together.
Among conventional input processing systems, which integrate a liquid crystal display and a coordinate input device (tablet) into one unit and can be used like paper, are Japanese Patent Laid-Open No. 88325/1986, UK Patent Application GB 2,193,827A and U.S. Pat. No. 4,730,186.
As a conventional example of technique that provides coordinate correspondence between liquid crystal elements and a coordinate input device (tablet), there is Japanese Patent Laid-Open No. 183428/1984 (U.S. Pat. No. 4,646,073). Further, Japanese Patent Laid-Open No. 36330/1988 discloses a system that allows 90-degree rotations of contents shown on the liquid crystal display, in addition to a normal display, for use with customer services at windows. Japanese Patent Laid-Open No. 73203/1993 offers a system which allows a paper frame to be moved or rotated as desired, bringing the ease of use a step closer to that of paper.
Another example of conventional information processing device, as disclosed by Japanese Patent Laid-Open Nos. 127714/1990, 15717/1992, and 15725/1992, employs a plurality of displays, each bonded with a tablet, through which information is input and output, to improve man-machine interface performance. Japanese Patent Laid-Open No. 278658/1992 discloses a system which consists of a plurality of liquid crystal display elements capable of both-side display, stacked together like a book, allowing the user to turn over the display elements like pages so that he or she can grasp the entire information in the same way as in a book.
In the above-mentioned conventional arts, the display and the tablet are physically integrated in construction and the relation between display and input is fixed. This construction has some drawbacks as it gives no considerations to the situations where the user may want to remove only a display and carry it freely; where the user may want to put the display at an arbitrary location on the desk (corresponding to the tablet or coordinate input device); or where the user may want to stack a plurality of displays together for a particular use.
In addition to the display and the tablet being integrated, the processing device is also a part of the integrated structure, giving rise to a limit to the reduction of weight and thickness. Further, when a plurality of displays are used, the cost is inhibitingly high.